1. Field of Invention
The invention concerns an apparatus for metering tobacco in portions suitable for packaging, comprising a feeding element for the tobacco and a device for forming and discharging at least one tobacco portion suitable for packaging. Furthermore the invention concerns a method for metering tobacco, in particular moist tobacco, in portions suitable for packaging.
2. Related Art
Apparatuses and methods of this kind are used in the tobacco-processing industry in order to process and in particular meter so-called snus tobacco. Snus tobacco is a so-called oral tobacco (or tobacco blends) which is introduced into the mouth directly or in a suitable package, e.g. a bag made of cellulose or the like, wherein the term “tobacco” includes not only exclusively the actual tobacco, but also tobacco with additives, aromas or the like. When unpackaged snus tobacco is taken, it is put directly in tins, boxes, combination packages or the like. The actual portioning suitable or ready for consumption is performed by the consumer himself. Snus tobacco which is taken in packaged form, namely e.g. in individual sealed-edge bags or the like, must be portioned and put in the bags beforehand. The tobacco portions, of which the weight and size can vary and is usually in the region of milligrammes and grammes, are divided off from a continuously or intermittently delivered flow of tobacco by means of metering devices and usually packaged by means of so-called sealed-edge bag machines, such as are known from DE 10 2005 017 474 A1.
From practical experience metering devices are known in which the feeding element is a funnel by means of which the tobacco is transported into the area of a device for forming and discharging a tobacco portion suitable for packaging. The known devices for forming and discharging the tobacco portions usually comprise a pre-portioning chamber or decompression chamber, which is connected to the funnel via a hose or the like. Inside the decompression chamber, the tobacco entering from the funnel is stored temporarily. Below the decompression chamber is usually arranged a microcylinder. By retracting the piston, tobacco is, so to speak, drawn out of the decompression chamber into the cylinder, wherein the volume of the portioning chamber formed by the retracted piston corresponds to a tobacco portion suitable for packaging. When the portioning chamber is full, the decompression chamber is moved relative to the microcylinder (or vice versa), so that the contents of the portioning chamber, namely one tobacco portion, can be discharged e.g. to a transport chamber or the like. This transport chamber can form e.g. a unit with the decompression chamber. After filling of the transport chamber with the metered tobacco portion, the transport chamber is moved into a dispensing position over an outlet opening, so that the tobacco portion drops down to a subsequent apparatus, namely e.g. the sealed-edge bag machine. While the transport chamber is over the outlet opening, the microcylinder can already again be filled with the next tobacco portion. Such metering devices are suitable for single-track and multiple-track sealed-edge bag machines.
Such metering devices have the drawback, however, that only free-flowing tobacco, that is, tobacco with a low residual moisture content, can be processed. To put it another way, only tobacco which has a residual moisture content of less than about 20% can be processed reliably. Even tobacco with a residual moisture content of less than about 20% to which additives are added can be processed only with difficulty or not at all, as the additives, aromas and the like further increase the moisture content, e.g. due to oils or the like. During the processing of such moist tobaccos, the tobacco adheres or sticks in particular in the area of the (partly curved) hoses or microcylinders, and after a short time leads to blockage of the device and hence stopping of the subsequent sealed-edge bag machine.